Field of the Invention
The present invention relates to flush valves, and more particularly, to diaphragms used in flush valves.
Description of Related Art
Flush valves in water closets, urinals, and other plumbing devices which utilize a flexible diaphragm to establish and to seal off the connection between the inlet and outlet are well-known in the art. Typically, the diaphragm is made of an elastomeric material, such as rubber, and includes a filter and bypass, which provides fluid communication between the inlet side of the flush valve and an upper chamber of the flush valve. Such flush valve diaphragms are described in U.S. Pat. Nos. 7,516,938 and 8,210,202, which are hereby incorporated by reference in their entirety.
The performance of prior art diaphragm-type flush valves can depend upon how well the diaphragm seals off the connection between the inlet and the outlet. The performance also depends on the pressure drop between the opposite sides of the diaphragm due to the bypass orifice. A diaphragm with a misaligned bypass orifice can prevent water from flowing to the top side of the diaphragm, which results in an inadequate seal. The correct positioning of the bypass orifice within the flush valve is paramount to ensuring that the proper pressure drop is established between the opposite sides of the diaphragm.
Accordingly, there is a general need in the art for a flush valve assembly and flush valve diaphragm that are configured so as to ensure correct positioning of the bypass orifice with respect to the body of the flush valve assembly during installation of the flush valve diaphragm and diaphragm assembly.